1. Field
One embodiment of the invention relates to a video decoding apparatus and a video decoding method which decodes a video stream which has been compressed and encoded.
2. Description of the Related Art
As standard technologies for encoding a video stream, H.261 and H.263 of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T), Moving Picture Experts Group (MPEG)-1, MPEG-2, and MPEG-4 of the International Organization for Standardization (ISO), and the like, have been developed. As a next-generation video encoding method in which the technologies such as H.261 to H.263, MPEG-1 to MPEG-4, and the like have been succeeded, and further developed, there is the H.264 which has been standardized by the ISO and the ITU jointly. In the H.264, a deblocking filter for relieving a distortion generated at a block boundary is used as one of filters in loop, which enhances a picture quality improvement effect at a low bit rate particularly (refer to ITU-T Recommendation H.264 (2003), “Advanced Video Coding for generic audiovisual services”|ISO/IEC 14496-10: 2003, “Information technology, Coding of audio-visual objects—Part 10: Advanced video coding”, and H.264/AVC textbook (Impress Communications Corporation)).
However, in a video decoding apparatus in accordance with standardization specifications based on the H.264, a proportion of the throughput of the deblocking filter accounting the entire decoding processing is practically high. Therefore, real-time decoding processing is made unable to be in time in a case of a system with low processing capacity, or when a load on the processing of an entire system is high, and there is possibility that defects in which frames are dropped, movement of an object is made extremely slow, and the like, are brought about.